On the competition between lateral convection and upward displacement in a multi-zone naturally ventilated space

Kuesters, Andrea S. and Woods, Andrew W. (2012) On the competition between lateral convection and upward displacement in a multi-zone naturally ventilated space. Journal of Fluid Mechanics, 707. pp. 393-404. DOI 10.1017/jfm.2012.287

[img] PDF (This is a RoMEO green journal)
Kuesters.pdf
Restricted to Registered users only

Download (778kB)
Official URL: http://journals.cambridge.org/abstract_S0022112012...

Abstract

We consider the flow which develops when two separate spaces maintained at different temperatures, both in excess of the exterior temperature, are connected through high and low level openings to a central atrium in which there is negligible heat load but which can naturally ventilate through high and low level openings to the exterior. We show that with a small temperature contrast between the spaces or large openings from the atrium to the exterior, upflow displacement ventilation develops in each of the spaces, with air entering from the atrium at low level and exiting at high level. However, with a larger temperature contrast between the spaces or small openings between the atrium and the exterior, a convective circulation develops between the spaces, with upflow in the warmer space and downflow in the colder space. Exterior air, which may enter the atrium at low level, flows into the warmer space along with the air from the colder space. At high level, air flows back into the atrium from the warmer space, and then either vents from the building or flows into the colder space. In this convection dominated flow regime, the colder space is a net heat sink, whereas with the upward displacement ventilation, this space acts as a net heat source. This can have significant implications for energy usage and on the build up of contaminants in each of the spaces. We also show that in both steady flow regimes, the air at mid-level in the atrium is unventilated and stagnant. We discuss the relevance of our model for controlled natural ventilation in large public buildings such as shopping malls where individual shops often maintain temperatures independently of the central atrium-space.

Item Type: Article
Uncontrolled Keywords: 2012AREP; IA64; BPI;
Subjects: 99 - Other
Divisions: 99 - Other
Journal or Publication Title: Journal of Fluid Mechanics
Volume: 707
Page Range: pp. 393-404
Identification Number: 10.1017/jfm.2012.287
Depositing User: Sarah Humbert
Date Deposited: 27 Oct 2012 12:32
Last Modified: 23 Jul 2013 10:05
URI: http://eprints.esc.cam.ac.uk/id/eprint/2616

Actions (login required)

View Item View Item

About cookies